Sewing machine

ABSTRACT

A sewing machine includes an embroidery frame which holds a cloth marked with a reference line and a reference point, a display portion which displays a virtual reference line, a virtual reference point, and an embroidery pattern having a size larger than the embroidery frame, means for displaying a sewing region corresponding to the embroidery frame on the display portion such that a section of the embroidery pattern, the virtual reference line and the virtual reference point are displayed inside the sewing region, means for acquiring position information of the reference point and another point on the reference line, sewing data correcting means for correcting sewing data on the embroidery pattern by interrelating the position information with the virtual reference line and the virtual reference point, and means for sewing the section of the embroidery pattern in accordance with the sewing data corrected by the sewing data correcting means.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims priority from Japanese Patent Application No. 2007-063753 filed on Mar. 13, 2007, the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a sewing machine for sewing an embroidery pattern, which is larger than an embroidery frame for holding a cloth, by dividing the embroidery pattern in several sections and sewing the respective sections in several steps.

DESCRIPTION OF RELATED ART

Related-art embroidery sewing machines have an embroidery frame (a holding frame) in which a cloth is set, and various embroidery patterns can be sewn onto the cloth. When sewing an embroidery pattern which is larger than the embroidery frame, there has been known a technique called “joining embroidering” (see, e.g., JP 11-047471 A). In the joining embroidering, the cloth is shifted and set onto the embroidery frame each time an embroidering within the embroidery frame is completed.

In the joining embroidering, moreover, cross lines are previously marked on the cloth with a chalk pencil so that relative positions of a part of the embroidery pattern which has already been sewn and another embroidery pattern which is going to be sewn are not shifted from each other. More specifically, the cloth may be positioned and set with respect to the embroidery frame while using the cross lines as a reference, or the cross lines may be recognized by an embroidery sewing machine as a reference positioning a needle with respect to the cross lines on the cloth set in the embroidery frame.

However, in order to recognize the cross lines in an related-art embroidery sewing machine disclosed in the JP 11-047471 A for example, it is necessary to position the needle with respect to four points on the cross lines, namely, two points on a vertical line and two points on a transverse line, and to input and store positions of the embroidery frame corresponding to the respective positions. Because a fine adjustment is required repetitively to accurately perform the positioning at the respective positions on the cross lines, it is onerous for an operator so that a working efficiency is deteriorated.

Moreover, because the cross lines marked with the chalk pencil is thicker than a tip of the needle, a positional error of the needle in thickness directions of the respective cross lines needs to be permitted. Thus, there has been a disadvantage that the positional error of the needle might become large as the number of the points to be positioned is increased.

SUMMARY OF THE INVENTION

One or more exemplary embodiments of the present invention provide a sewing machine in which a labor of an operator is reduced and sewing accuracy of a joining embroidering is improved.

According to one or more exemplary embodiments of the present invention, a sewing machine includes an embroidery frame which holds a cloth on which a reference line and a reference point on the reference line are marked, a display portion which displays an embroidery pattern, which is to be sewn in a range larger than the embroidery frame, a virtual reference line, and a virtual reference point on the virtual reference line, such that the embroidery pattern is associated with or in relation to the virtual reference line and the virtual reference point which are references for a position and an angle upon embroidering the embroidery pattern on the cloth, display control means for displaying a sewing region, which corresponds to the embroidery frame, on the display portion such that a section of the embroidery pattern, the virtual reference line and the virtual reference point are displayed inside the sewing region, reference position information acquiring means for acquiring position information of the reference point and another point on the reference line, sewing data correcting means for correcting sewing data on the embroidery pattern in accordance with an arrangement of the cloth by interrelating the position information acquired by the reference position information acquiring means with the virtual reference line and the virtual reference point, and sewing control means for sewing the section of the embroidery pattern included in the sewing region onto the clot in accordance with the sewing data corrected by the sewing data correcting means.

Other aspects and advantages of the invention will be apparent from the following description, the drawings and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a sewing machine according to an exemplary embodiment of the present invention;

FIG. 2 is a block diagram showing a part of a configuration of the sewing machine;

FIG. 3 is a plan view showing an example of an operation panel of the sewing machine;

FIG. 4 is a flowchart showing a process of sewing a large-sized embroidery pattern onto a cloth;

FIG. 5 is an explanatory view showing a comparison between an embroidery frame and the large-sized embroidery pattern;

FIG. 6 is a plan view showing an example of a display mode of the operation panel;

FIG. 7 is an explanatory view of a reference line and a reference point which are marked on the cloth;

FIG. 8 is a plan view showing another display mode of the operation panel;

FIG. 9 is a plan view showing another display mode of the operation panel;

FIG. 10 is a plan view showing another display mode f the operation panel;

FIG. 11 is an explanatory view showing an example of a correction of sewing data; and

FIG. 12 is a plan view showing another display mode of the operation panel.

DETAILED DESCRIPTION

Hereinafter, an exemplary embodiment of the invention will be explained with reference to the drawings. The following exemplary embodiment does not limit the scope of the invention.

A sewing machine according to the exemplary embodiment is an embroidery sewing machine M. The embroidery sewing machine M has an embroidery frame 11 for holding a cloth (a workpiece) to be sewn. The embroidery sewing machine M is operable to form stitches on the cloth held in the embroidery frame 11 in accordance with sewing data by relatively moving the embroidery frame 11 with respect to a needle 8.

In the following description, a Z-axis direction (or an up-and-down direction) is a direction along which the needle 8 vertically moves, an X-axis direction (a right-and-left direction) is a direction orthogonal to the Z-axis direction, and a Y-axis direction (a front-and-rear direction) is a direction orthogonal to the Z-axis direction and the X-axis direction.

As shown in FIGS. 1 and 2, The embroidery sewing machine M (hereinafter “sewing machine M”) includes a sewing machine body 1 and a frame moving mechanism 13 provided on the sewing machine body 1.

As shown in FIG. 1, the sewing machine body 1 includes a sewing machine frame 2 having a C shape when seen from a side. The sewing machine frame 2 includes an arm portion 2 a extending in the X-axis direction in an upper part of the sewing machine M, a bed portion 2 b extending in the X-axis direction in a lower part of the sewing machine M, and a vertical drum portion 2 c coupling the arm portion 2 a and the bed portion 2 b.

The sewing machine body 1 further includes a sewing machine driving mechanism provided in the sewing machine frame 2. The sewing machine driving mechanism includes an upper shaft (not shown) and a lower shaft (not shown) which are rotatable and are extended in the X-axis direction. The upper shaft is provided in the arm portion 2 a and the lower shaft is provided in the bed portion 2 b.

The upper shaft is coupled to a sewing machine motor 5 (see FIG. 2), and a rotating force is applied from the sewing machine motor 5. The lower shaft is coupled to the upper shaft via a power transmitting mechanism (not shown). When the upper shaft is rotated, a power of the upper shaft is transmitted to the lower shaft through the power transmitting mechanism so that the lower shaft is rotated.

A needle bar 8 a is coupled to a front end portion of the upper shaft. The needle bar 8 a is vertically movable in the Z-axis direction in accordance with the rotation of the upper shaft. The needle 8 is exchangeably provided on a lower end of the needle bar 8 a. Moreover, a middle presser 12 is provided on the sewing machine arm 2 a in order to prevent the cloth from being lifted up due the a vertical movement of the needle 8. The middle presser 12 is vertically movable interlockingly with the needle bar 8 a, and presses the cloth around the needle 8.

A shuttle (not shown) is provided on a front end portion of the lower shaft. When the lower shaft is rotated together with the upper shaft, stitches are formed by a cooperation of the needle 8 and the shuttle.

Because the coupling structures and movements of the sewing machine motor 5, the upper shaft, the needle bar 8 a, the needle 8, the lower shaft and the shuttle are similar to those in the related art sewing machines, detailed description thereof will be omitted.

As shown in FIG. 1, the frame moving mechanism 13 is disposed on the bed portion 2 b. The frame moving mechanism 13 includes a carriage 13 a and an attaching member 13 b to which the embroidery frame 11 is attached. The embroidery frame 11 and the needle 8 are disposed on the bed portion 2 b.

The embroidery frame 11 is attached to the frame moving mechanism 13 via the attaching member 13 b. An X-axis motor 14 and a Y-axis motor 15 (see FIG. 2) are coupled to the attaching member 13 b. In the exemplary embodiment, the X-axis motor 14 and the Y-axis motor 15 are pulse motors, and may be disposed inside the bed portion 2 b or inside the carriage 13 a.

The embroidery frame 11 is movable in the front-and-rear direction and in the right-and-left direction (i.e., in the X and Y directions) together with the cloth held therein in accordance with driving operations of the X-axis motor 14 and the Y-axis motor 15, thereby positioning the cloth with respect to the needle 8. By interlocking the movement of the embroidery frame 11 with the operations of the needle 8 and the shuttle, stitches are formed on the cloth by the needle 8 in accordance with sewing data (e.g., sewing data on an embroidery pattern having a size larger than the embroidery frame 11). The stitches corresponding to an embroidery pattern are formed on a portion of the cloth on an inner side of the embroidery frame 11, i.e., inside a stitchable range of the embroidery frame 11.

In other words, the sewing machine M includes the embroidery frame 11 having the inner side thereof being the stitchable range, and the embroidery pattern corresponding to the sewing data is formed on the cloth held within the stitchable range of the embroidery frame 11.

As shown in FIGS. 1 and 2, the sewing machine M further includes key matrix 16. The key matrix 16 includes a start/stop switch 16 a, a reverse stitching switch 16 b, a thread cutting switch 16 c and a speed regulating volume 16 d.

The key matrix 16 serves as an operation key for driving the sewing machine M to move the needle bar 8 a (the needle 8) and to operate the embroidery frame 11. More specifically, signals are output to a control portion 100 in response to operations of the key matrix 16, and the control portion 100 drives the sewing machine motor 5 and others to drive the sewing machine M in accordance with the signals.

The sewing machine M further includes an operation panel 20 from which an operator caries out various setting operations and inputting operations of various data with respect to the sewing machine M. The operation panel 20 and the control portion 100 are coupled to each other via a line which is not shown.

As shown in FIG. 2, the operation panel 20 includes a liquid crystal display panel 22 (a display portion) and a touch panel 21 disposed on a display panel of the liquid crystal display panel 22 (on a front side of the display panel). The touch panel 21 serves as a transparent touch switch. More specifically, when a key displayed on the liquid crystal display panel 22 is touched, the touch panel 21 detects a position of the touch on the touch panel 21. The detection may be an electromagnetic induction type, a magnetic strain type or a pressure sensitive type. Various data and instructions can be input in accordance with the position thus detected. For example, when a operation key displayed on the operation panel 20 is touched, the display mode of the liquid crystal display panel 22 may be switched to display various operation screens, operation keys, and various set data. A signal input by touching the operation panel 20 is output to the control portion 100. Accordingly, the operation panel 20 functions as an input portion and the display portion of the sewing machine M.

As shown in FIG. 3, the liquid crystal display panel 22 has a display region 22 a on which the embroidery pattern is displayed.

A group of operation keys to be displayed on the operation panel 20 includes an eight-direction key 21 a, an OK key 21 b and a coordinate acquiring key.

In addition to the group of operation keys, the liquid crystal display panel 22 of the operation panel 20 displays, on the display area 22 a, various embroidery patterns, a virtual reference line Lv, a virtual reference point Pv, and a sewing region R corresponding to the stitchable range of the embroidery frame 11. The virtual reference line Lv and the virtual reference point Pv are used as references upon a sewing work. A layout image of the entire embroidery pattern, and a sectioned image of the embroidery pattern corresponding to the sewing region R are displayed on the display area 22 a.

As shown in FIG. 2, the sewing machine M further includes the control portion 100 to which the sewing machine motor 5, the X-axis motor 14, the Y-axis motor 15, the operation panel 20 and the key matrix 16 are coupled.

The control portion 100 includes a CPU 101 operable to executes various processings and controls in accordance with a control program with respect to the sewing machine motor 5, the X-axis motor 14, the Y-axis motor 15, the operation panel 20 and the other actuators which are not shown, an ROM 102 (a storing portion) in which programs for executing various processings and controls and data required for the various processings and controls are stored, an RAM 103 which serves as a work area for various processings by storing various data therein, an EEPROM 104 serving as another storing portion in which data can be newly written and from which data can be deleted, interfaces (not shown) via which the CPU 101 is coupled to various devices, and motor drivers (not shown) for the respective motors.

The CPU 101 is operable to control the operation processings of the respective portions of the sewing machine M in accordance with the various control programs for the embroidering stored in the ROM 102 and various sewing data stored in the EEPROM 104 in response to the operation signals input from the key matrix 16 and various setting signals and data input from the operation panel 20, store a result of the processings in the work area in the RAM 103, and further store, in the EEPROM 104, the various data input from the operation panel 20 and the result of the processings stored in the RAM 103 if necessary.

The CPU 101 functions as control means for controlling the driving operations of the respective portions of the sewing machine M.

The control programs and control data for the sewing machine M, and data on various sewing operations and display screen information are stored in the ROM 102.

For example, sewing data for each of the embroidery patterns are previously stored in the ROM 102. The sewing data includes coordinates of points indicative of a shape of stitches (shape point data) and coordinates of stitch points which are calculated based on the shape points (stitch point data). In other words, coordinate data (coordinate points) on the stitch points in relation to positions of the needle 8 with respect to the embroidery frame 11 are stored as sewing data. Moreover, moving amount data on moving amounts of the embroidery frame 11 for relatively moving the embroidery frame 11 with respect to the needle 8 are stored in the ROM 102 in order to sequentially locate the needle 8 at the positions according to the coordinate data.

In addition, coordinate data on an origin point of the embroidery frame 11, which is a base point in the movement of the embroidery frame 11, is stored in the ROM 102. Based on the origin coordinates, the embroidery frame 11 is moved and the coordinates of the stitch points are acquired.

Furthermore, data on a function indicative of the virtual reference line Lv, which is used when the joining embroidering is selected, is stored in the ROM 102 (e.g., data on cross lines to be a reference index).

The RAM 103 includes various work memories and counters, and is used as the work area while processing the input data and during the sewing operation.

Sewing data other than the data stored in the ROM 102, display screen information, and sewing data set by the operator from the operation panel 20, are stored in the EEPROM 104.

The sewing data to be stored in the EEPROM 104 include sewing data on a composite embroidery pattern obtained by arranging and combining embroidery patterns stored in the ROM 102 with an optional layout.

The sewing data to be stored in the EEPROM 104 include shape point data and stitch point data (coordinate data and moving amount data) which are created by adjusting, in accordance with a layout and an enlargement/reduction of a size of a pattern, the shape point data and the stitch point data of the sewing data on the embroidery patterns stored in the ROM 102.

The control portion 100 processes operation signals input from an X-axis origin sensor (not shown) and a Y-axis origin sensor (not shown) which are provided in the X-axis motor 14 and the Y-axis motor 15 respectively, operation signals input from the switches 16 a to 16 c and the volume 16 d of the key matrix 16, various setting data input from the operation panel 20 and various data stored in the ROM 102 and the EEPROM 104 in accordance with various control programs stored in the ROM 102, and executes a control of the operation panel 20, the X-axis motor 14, the Y-axis motor 15 and the sewing machine motor 5.

Upon executing a sewing, the control portion 100 carries out a processing of control means in which the CPU 101 executes the control program to read the sewing data stored in the ROM 102 and/or the EEPROM 104 to start the driving operation of the sewing machine motor 5 and to drive the X-axis motor 14 and the Y-axis motor 15 in order to position the embroidery frame 11 at stitch point of the needle 8 indicated by the sewing data. The control portion 100 sequentially positions the embroidery frame 11 at the respective stitch points in accordance with the coordinate data of the sewing data interlockingly with the rotation of the sewing machine motor 5, and continuously carries out stitching of the needle 8 until the entire sewing work is completed. In this way, an embroidery pattern is formed on the cloth.

Moreover, the control portion 100 executes a control for displaying, on the display area 22 a of the liquid crystal display panel 22, an embroidery pattern having a larger range than the embroidery pattern 11, in relation to the virtual reference line Lv and the virtual reference point Pv on the virtual reference line Lv which are used as references of a position and an angle when sewing the embroidery pattern onto the cloth.

Further, the control portion 100 functions as display control means for displaying the sewing region R corresponding to the embroidery frame 11 at an optional position on the display area 22 a such that a part of the embroidery pattern, the virtual reference line Lv and the virtual reference point Pv are included in the sewing region R.

More specifically, the control portion 100 (the display control means) executes a control for moving the sewing region R corresponding to the size (the stitchable range) of the embroidery frame 11 to an optional position on the display area 22 a of the liquid crystal display panel 22 and for displaying the sewing region R so as to surround a part of the embroidery pattern displayed on the display area 22 a, the virtual reference line Lv and the virtual reference point Pv.

Further, the control portion 100 functions as reference position information acquiring means for acquiring position information on positions of a reference point P and an optional point on a reference line L which are marked on the cloth held in the embroidery frame 11.

More specifically, the control portion 100 (the reference position information acquiring means) executes a control for moving the embroidery frame 11 in accordance with a touching operation of the eight-direction key 21 a of the operation panel 20 to relatively move the needle 8 with respect to the embroidery frame 11, thereby positioning the needle 8 at the reference point P and the optional point on the reference line L on the cloth held in the embroidery frame 11 respectively and acquiring the position information, e.g., coordinates of the two points.

The control portion 100 (the reference position information acquiring means) acquires a function of the reference line L on the cloth held in the embroidery frame 11 by calculating a line connecting the reference point P and the optional point on the reference line L in accordance with the coordinate data of the two points.

Moreover, the control portion 100 functions as sewing data correcting means for correcting sewing data on the embroidery pattern in accordance with a position of the cloth based on the position information acquired by the control portion 100 (the reference position information acquiring means) by interrelating the position information with respect to the virtual reference line Lv and the virtual reference point Pv.

More specifically, the control portion 100 (the sewing data correcting means) executes a control for correcting the sewing data on the embroidery pattern such that a difference of positions (coordinates) between the reference point P and the virtual reference point Pv and a difference of inclinations between the reference line L and the virtual reference line Lv are compensated, whereby an embroidery to be actually sewn onto the cloth is formed at a desirable position and angle. In other words, the control portion 100 (the sewing data correcting means) carries out a control of correcting a positional shift and a inclination shift of cross lines, an intersection point of which being the reference point P on the function of the reference line L acquired by the control portion 100 (the reference position information acquiring means), with respect to the cross lines, an intersection point of which being the virtual reference point Pv on the virtual reference line Lv, so that the embroidery pattern, which is displayed on the display area 22 a of the operation panel 20 with the virtual reference line Lv and the virtual reference point Pv being the references, is formed on the cloth held in the embroidery frame 11.

Further, the control portion 100 functions as the sewing control means for sewing a part of the embroidery pattern included in the sewing region R onto the cloth based on the sewing data corrected by the control portion 100 (the sewing data correcting means).

The control portion 100 (the sewing control means) executes an operation for sewing each portion of the sectioned embroidery pattern such that the reference line L and the reference point P, which are marked on the cloth, correspond to the virtual reference line Lv and the virtual reference point Pv, which are included in the sewing region R, respectively, thereby combining and joining the sectioned embroidery patterns to form the entire embroidery pattern onto the cloth.

With regard to the joining embroidering, the operation and processing for sewing a part of the embroidery pattern included in the sewing region R onto the cloth is similar to that in the related art. Therefore, detailed description thereof will be omitted.

Next, the process to be carried out in the sewing machine M according to the exemplary embodiment when sewing an embroidery pattern, which is larger than the size of the embroidery frame 11, onto the cloth will be described with reference to the flowchart of FIG. 4.

In the exemplary embodiment description will be given by taking, as an example, an operation for sewing an embroidery pattern which is four times larger than the stitchable range of the embroidery frame 11 as shown in FIG. 5.

First of all, sewing data on a heart-shaped pattern and sewing data on a smile-shaped pattern, which are stored in the ROM 102, are read respectively through a key operation of the operation panel 20 by the operator, and the respective embroidery patterns are arranged in a layout on the display area 22 a of the operation panel 20 on which the virtual reference line Lv and the virtual reference point Pv are displayed, and a desirable large-sized embroidery pattern is created by combining the heart-shaped patterns and the smile-shaped patterns as shown in FIG. 6, and sewing data on the large-sized embroidery pattern thus created are stored in the EEPROM 104 (Step S101).

As shown in FIG. 7, the reference line L and the reference point P are marked, with a chalk pencil, on the cloth C on which the large-sized embroidery pattern is to be sewn. The operator marks the reference line L and the reference point P on the cloth C with the chalk pencil such that the reference line L and the reference point P corresponds to the virtual reference line Lv and the virtual reference point Pv, which are displayed on the display area 22 a in relation to the large-sized embroidery pattern, respectively.

As shown in FIG. 6, on the display area 22 a of the operation panel 20, the virtual reference line Lv is displayed as a vertical line, and the virtual reference point Pv is displayed as an intersection point of the virtual reference line Lv and a transverse line perpendicular to the virtual reference line Lv. On the other hand, as shown in FIG. 7, a mark line forming an intersection point with the reference line L is marked on the cloth C to indicate the reference point P corresponding to the virtual reference point Pv.

Subsequently, as shown in FIG. 8, the sewing region R corresponding to the stitchable range of the embroidery frame 11 is displayed on the display area 22 a and is moved through an operation from the eight-direction key 21 a of the operation panel 20 by the operator or an operation for designating the display area 22 a through a direct touch, and the OK key 21 b is touched at a desirable position in which the sewing region R includes a part of the large-sized embroidery pattern, and the virtual reference line Lv and the virtual reference point Pv, thereby designating and setting the sewing region R corresponding to a range in which the sewing machine M sews the embroidery (Step S102).

When the OK key 21 b is touched, then, a range surrounded by the sewing region R (see FIG. 8), that is, a part of the large-sized embroidery pattern, and the virtual reference line Lv and the virtual reference point Pv within the range are enlarged and displayed on the entire display region 22 a of the operation panel 20 as shown in FIG. 9.

The virtual reference line Lv and the virtual reference point Pv, which are displayed on the display region 22 a of the operation panel 20, serves as indices to show which portion of the cloth C is to be held in the embroidery frame 11.

Subsequently, the operator attaches, to the embroidery frame 11, the cloth C having the reference line L and the reference point P marked thereon, and holds the cloth C by referring to the virtual reference line Lv and the virtual reference point Pv displayed on the display region 22 a of the operation panel 20 shown in FIG. 9. More specifically, the display region 22 a of the operation panel 20 shown in FIG. 9 is a range surrounded by the sewing region R and corresponds to the stitchable range in the embroidery frame 11. Therefore, it is preferable to attach the cloth C to the embroidery frame 11 so as to dispose the reference line L and the reference point P with respect to the embroidery frame 11 in way the virtual reference line Lv and the virtual reference point Pv are displayed on the display region 22 a.

After the clot C is attached to the embroidery frame 11, the operator touches the OK key 21 b of the operation panel 20 shown in FIG. 9.

When the OK key 21 b is touched by the operator, a reference line designating key 21 c and a reference point designating key 21 d, which are coordinate acquiring keys functioning as a part of the reference position information acquiring means, are displayed on the operation panel 20 together with the eight-direction key 21 a and the OK key 21 b as shown in FIG. 10.

Subsequently, the operator manipulates the eight-direction key 21 a to move the embroidery frame 11, thereby relatively moving the needle 8 with respect to the embroidery frame 11. The needle 8 is positioned at optional point on the reference line L on the cloth C held in the embroidery frame 11 and the reference line designating key 21 c is touched to acquire coordinate data on the optional point on the reference line L. Subsequently, the operator manipulates the eight-direction key 21 a to move the embroidery frame 11, thereby relatively moving the needle 8 with respect the embroidery frame 11. The needle 8 is then positioned at the reference point P on the cloth C held in the embroidery frame 11 and the reference point designating key 21 d is touched to acquire coordinate data on the reference point P. The optional point on the reference line L and the reference point P are set to be different from each other.

Then, the control portion 100 obtains a line connecting the reference point P and the optional point on the reference line L by calculating from the coordinate data on the two points which are acquired. Accordingly, a function of the reference line L on the cloth C, which is actually attached and held in the embroidery frame 11, is acquired (Step S103).

When the reference line designating key 21 c and the reference point designating key 21 d are touched and the OK key 21 b is then touched by the operator, the control portion 100 carries out a correction processing in which the sewing data on the embroidery pattern, which is displayed on the display area 22 a of the operation panel 20 with the virtual reference line Lv and the virtual reference point Pv being the references, is transformed into sewing data for an actual sewing onto the cloth C held in the embroidery frame 11. More specifically, the control portion 100 transforms an arrangement of the virtual reference line Lv and the virtual reference point Pv such that the cross lines formed by the virtual reference line Lv and the transverse line passing through the virtual reference point Pv and perpendicularly intersecting the virtual reference line Lv is superposed on the cross lines formed by the function of the reference line L and a line perpendicularly intersecting the reference line L at the reference point P (Step S104).

Data on the cross lines formed by the virtual reference line Lv and the transverse line passing through the virtual reference point Pv and perpendicularly intersecting the virtual reference line Lv (e.g., respective functions of the virtual reference line Lv and the intersecting transverse line) are previously stored in the ROM 102.

For example, in a case in which the cross lines including the reference line L and the cross lines including the virtual reference line Lv are shifted from each other by an angle θ as shown in FIG. 11, there is carried out a correction processing of adjusting the coordinates of stitch points in the sewing data by a transformation of rotating and moving the sewing data on the embroidery pattern displayed on the display area 22 a by the angle θ.

In a case in which positions of the cross lines including the reference line L and the cross lines including the virtual reference line Lv are shifted from each other by a distance z, there is carried out a correction processing of adjusting the coordinates of the stitch points in the sewing data by a transformation of moving the sewing data on the embroidery pattern displayed on the display area 22 a by the distance z in parallel. Moreover, it is also possible to carry out a correction processing of executing both a correction by the transformation of rotating and moving the sewing data by the angle θ and the correction the transformation of moving the sewing data by the distance z in parallel.

When the correction processing of transforming (converting) the sewing data on the embroidery pattern is carried out by the control portion 100, an embroidery pattern corresponding to the corrected sewing data is displayed on the display area 22 a of the operation panel 20. More specifically, as shown in FIG. 12, the embroidery pattern is displayed such that it is oriented in a direction in which a sewing is actually performed on the cloth C so as to correspond to a state in which the cloth C is held in the embroidery frame 11, i.e., in a state in which the cloth C has a positional shift or a tilt with respect to the embroidery frame 11 with the reference line L being the reference.

When the start/stop switch 16 a of the sewing machine M is manipulated by the operator, there is executed a sewing operation for sewing the embroidery pattern displayed on the display area 22 a of the operation panel 20 onto the cloth C held in the embroidery frame 11 (Step S105). The embroidery patterns which can be sewn by the sewing machine M are displayed on the display area 22 a of the operation panel 20 without their shapes being broken, e.g., two heart-shaped patterns and two smile-shaped patterns displayed on the display area 22 a in FIG. 12 can be sewn.

Moreover, the control portion 100 temporarily stores, in the RAM 103, a part of the large-sized embroidery pattern which has already been sewn (e.g., the two heart-shaped patterns and the two smile-shaped patterns arranged in a left upper area of the large-sized embroidery pattern).

Subsequently, the control portion 100 decides whether the entire large-sized embroidery pattern has been sewn or not (Step S106).

If the control portion 100 decides that the entire large-sized embroidery pattern has not yet been sewn (Step S106; No), the processing returns to Step S102. Thus, the processing is continuously carried out to consecutively execute an operation for sewing the residual embroidery pattern. It is preferable that the control portion 100 display the portion of the large-sized embroidery pattern which has already been sewn and the rest of the large-sized embroidery pattern which has not yet been sewn on the display area 22 a of the operation panel 20 so as to be distinguishable from each other so that the operator can easily designate the portion which has not yet been sewn with the sewing region R.

With regard to the joining embroidering, the operation and processing for sewing, onto the cloth C, each portion of the embroidery pattern included in the sewing region R to form the entire embroidery pattern onto the cloth C is similar to that in the related art. Therefore, detailed description thereof will be omitted.

If the control portion 100 decides that the entire large-sized embroidery pattern has been sewn (Step S106; Yes), the processing of sewing the large-sized embroidery pattern onto the cloth C is ended, and the operation of the sewing machine M is stopped.

As described above, the sewing machine M is operable to perform a joining embroidering of the entire large-sized embroidery pattern onto the cloth C by repetitively executing of the pattern sewing operation corresponding to the region designated to divide the large-sized embroidery pattern by the sewing region R and by combining the sectioned embroidery patterns.

When forming the large-sized embroidery pattern onto the cloth C with the sewing machine M, it is possible to accurately perform the joining embroidering with by dividing the large-sized embroidery pattern with the sewing region R and connecting the embroidery patterns thus sectioned.

In other words, when the large-sized embroidery pattern displayed on the display area 22 a of the operation panel 20 is to be sectioned into some portions to be sewn onto the cloth C while causing the virtual reference line Lv and the virtual reference point Pv, which are displayed in relation to the large-sized embroidery pattern, to correspond to the reference line L and the reference point P, which are marked on the cloth C held in the embroidery frame 11 in the sewing machine M, it is possible to accurately perform the joining embroidering by sewing the embroideries in the some sectioned portions into proper positions of the cloth C and combining the embroideries in the sectioned portions to form the large-sized embroidery pattern onto the cloth C.

Specifically, the operator only needs to position the needle 8 at two points to set the cross lines that are used when interrelating the virtual reference line Lv and the virtual reference point Pv in the display area 22 a with respect to the reference line L and the reference point P which are marked on the cloth C held in the embroidery frame 11, respectively. More specifically, the operator positions the needle 8 at the optional point on the reference line L on the cloth C held in the embroidery frame 11 and at the reference point P on the cloth C to acquire the coordinate data on the two points, whereby the cross lines are set from the function of the reference line L and the function of the line perpendicularly intersecting the reference line L at the reference point P. Therefore, it is possible to decrease the number of the positioning works as compared with the related art technique, thereby relieving the complicated work.

In the case in which the cross lines on the cloth is input by positioning the needle at four points on the cloth as in the related art, it is hard to set and input the cross lines such that the vertical line and the transverse line perpendicularly intersect each other (although the cross lines may be visually checked that they seem to be perpendicular to each other, it is difficult to input the cross lines that are accurately perpendicular to each other). However, according to the sewing machine M of the exemplary embodiment, it is possible to set the cross lines, in which the vertical line and the transverse line are accurately perpendicular to each other, by setting the function of the reference line L from the line connecting the two points at which the needle 8 are positioned and by further setting the function of the line perpendicularly intersecting the reference line L at the reference point P. Therefore, it is possible to form a more suitable joining embroidering.

According to the sewing machine M described above, it is possible to reduce the labor of the operator and to enhance sewing accuracy of the joining embroidering.

Although the embroidery pattern to be sewn has the size that is four times larger than the stitchable range of the embroidery frame 11 in the exemplary embodiment, an embroidery pattern having any size can be sewn.

Although the reference line L is marked the vertical direction on the cloth C in the exemplary embodiment, the reference line L may be marked in other directions. For example, if embroidery patterns are arranged in the vertical direction so that the reference line L in the vertical direction is difficult to recognize, the reference line L can be marked in a transverse direction. In such a case, the transverse line of the display area 22 a serves as the virtual reference line Lv.

While description has been made in connection with an exemplary embodiment of the present invention, those skilled in the art will understand that various changes and modification may be made therein without departing from the present invention. It is aimed, therefore, to cover in the appended claims all such changes and modifications falling within the true spirit and scope of the present invention. 

1. A sewing machine comprising: an embroidery frame which holds a cloth on which a reference line and a reference point on the reference line are marked; a display portion which displays an embroidery pattern, which is to be sewn in a range larger than the embroidery frame, a virtual reference line, and a virtual reference point on the virtual reference line, such that the embroidery pattern is associated with the virtual reference line and the virtual reference point which are references for a position and an angle upon embroidering the embroidery pattern on the cloth; display control means for displaying a sewing region, which corresponds to the embroidery frame, on the display portion such that a section of the embroidery pattern, the virtual reference line and the virtual reference point are displayed inside the sewing region; reference position information acquiring means for acquiring position information of the reference point and another point on the reference line; sewing data correcting means for correcting sewing data on the embroidery pattern in accordance with an arrangement of the cloth by interrelating the position information acquired by the reference position information acquiring means with the virtual reference line and the virtual reference point; and sewing control means for sewing the section of the embroidery pattern included in the sewing region onto the cloth in accordance with the sewing data corrected by the sewing data correcting means.
 2. The sewing machine according to claim 1, wherein the sewing data correcting means corrects the sewing data on the embroidery pattern such that the virtual reference line and the virtual reference point, which are displayed on the display portion in association with the embroidery pattern, are transformed so as to be superposed on the reference line and the reference point in accordance with the position information acquired by the reference position information acquiring means.
 3. The sewing machine according to claim 1, wherein the sewing control means forms the other sections of the embroidery pattern such that all the sections of the embroidery patterns are combined to form the embroidery pattern on the cloth.
 4. A sewing machine comprising: an embroidery frame which holds a cloth on which a reference line and a reference point on the reference line are marked; a display portion which displays an embroidery pattern, which is to be sewn in a range larger than the embroidery frame, a virtual reference line, and a virtual reference point on the virtual reference line, such that the embroidery pattern is in relation to the virtual reference line and the virtual reference point which are references for a position and an angle upon embroidering the embroidery pattern on the cloth; display control means for displaying a sewing region, which corresponds to the embroidery frame, on the display portion such that a section of the embroidery pattern, the virtual reference line and the virtual reference point are displayed inside the sewing region; reference position information acquiring means for acquiring position information of the reference point and another point on the reference line; sewing data correcting means for correcting sewing data on the embroidery pattern in accordance with an arrangement of the cloth by interrelating the position information acquired by the reference position information acquiring means with the virtual reference line and the virtual reference point; and sewing control means for sewing the section of the embroidery pattern included in the sewing region onto the cloth in accordance with the sewing data corrected by the sewing data correcting means.
 5. The sewing machine according to claim 4, wherein the sewing data correcting means corrects the sewing data on the embroidery pattern such that the virtual reference line and the virtual reference point, which are displayed on the display portion in association with the embroidery pattern, are transformed so as to be superposed on the reference line and the reference point in accordance with the position information acquired by the reference position information acquiring means.
 6. The sewing machine according to claim 4, wherein the sewing control means forms the other sections of the embroidery pattern such that all the sections of the embroidery patterns are combined to form the embroidery pattern on the cloth. 